Receiver arrangement for wireless telegraphy.



G. JAHR.

RECEIVER ARRANGEMENT FOR WIRELESS TELEGRAPHY.

APPLICATION FILED JUNE 12, 1907.

905,537. Patented Dec. 1, 1908.

m mlllmllhh UNITED STATES PATENT ormcn.

GERHARD .TAHR, or BER-LIN, GERMANY.

RECEIVER ARRANGEMENT Fon wmnmas's 'rELEenArHY.

Specification otLetteru Patent.

Patented Decal, 31.908".

Application filed June 12, 1907. Serial No. 378,536.

To all whom it may concern:.

Be it known that I, GERHARD J AHK, a subject of the King of Prussia, residing at Turmstrasse 47, Berlin, Germany, have invented certain new and useful Improvements in the Receiver Arrangement for Wireless Telegraphy; and -I do hereby declare the following to be a. full, clear, and

exact description of the invention, such as will enable others skilled ,in the art to which itappertains to inake and use the same, reference being had to the accompanying'drawings, and to letters or figures of reference marked thereon, which form a part of this specification. g

The subject matter of the present application is a receiver-arrangement for wireless telegraphy the essential feature of which consists in the antenna not being earthed but being ledthrough a coil of wire and connected with one pole of the coherer-or another receiving appartus; the end of'the coil at which the antenna enters into the in terior of the coil being connected with the other pole of the coherer while the'other' end of the coil is earthed. The coherer servesin the wellknown manner for closing a. local circuit containing the recording apparatus;

By .using the coil it is possible for themherer to workeven when the electric waves are very feeble. j The sensibility is still further increased if the part of the antenna which is inside\the coilor the coil consists of very thin wire and is wound in the form of-a helix.

' Instead of the ordinary coherer which al-' ways requires a separate tapping device for the purpose of doing away with the connection formed by the coherence of the particles in the coherer a device may be employed which serves to open and close a circuit by means of the action-of static electricity and the essential features of which consist in the surface of the part of the device which is to be charged being very small, for example consisting only of a small metal pinor penoil", and also in that this part of the device I which is to be charged is not in electrical connection with any other conductive bodies but its conductor and that the device is'capable .of being adj usted readily and quickly in correspondence with the strength of the waves employed at the time. I

'Byomeans of this contrivance it is :possible to make the receiver work with certainty Y of the coil wire and be arranged in the form of a helix even in the case of very weak electric waves in cases in which other such like apparatus does not work. In comparison with the ordinary coherer the apparatus possesses the advantage that no separate device is necessary for the purpose of bringing about decoherence.

In devising this apparatus account has been taken-of the fact that the parts to he charged by the electric waves .and discharged must be limited in size as much as possible and that the capacity of the-partsto becharged must not he increased by connecting them with parts which conduct or .001-

lect static electricity, asfor example, local batteries, recording apparatus and so on, as

' is the case. in other "such like-apparatus the result of which is that it is impossible tor them to perform their functions when the electric waves are afieeble.

The invention is illustrated the accom panying drawings in which V Figure 1- shows the device and connections when an ordinary coherer is used and Fig. 2 the connections when instead of the coherer another receiver is .used forming alsopart of the invention.

Referring to Fig. l-theantenna'a is led through a .coil of wire I)- and is connected with the terminal 0 of the coherer e. The

coil 6 is not electrically connected with the antenna. That, end of the coil at which the .antenna'enters said coil is connected with a as shown in Fig. 2.

The receiver in this form of the invention preferably consists ofa two-armed lever -h pivotally mounted on the pillar g, the one arm at? of which lever in its position of rest restsflpn-ithe fixed contact 2', and .above the arnul h adjustable contact is is arranged against which the arm b rests when :on the arrival of electrical waves the lever is oscillated. As a result of this oscillation the a..-

pivoted at n and which with the aid of a suitable device for example by means ot a set screw 39 can be turned so that the (illstance of the contacts 70 and m from the'lever can be increased or decreased according to the strength of the waves employed. I

The contact 76 is connected with the antenna' a. The lever h in consequence of gravitation normally rests with its arm h on the fixed contact 2' and so closes a local circuit through i h and g. The lever h is connected to earth by means of the conductor 23, coil 6 and conductor a. This circuit 2' k 9 only serves for testing by means of a circuit indicator 7-, whether the receiver is in good condition or not. On the arrival of electrical waves the lever h is oscillatedin virtue of which the arm h is brought into contact with the charged contact in and the arm k with the contact m so that a local circuit is closed through 9 h [L2 and m while the circuit through 2' h and g is broken. After 70 has been discharged the lever it drops back again into its position of rest the local circuit 9 k and m being broken. In this local circuit the recording apparatus 8 is arranged in the well-known manner with local battery 7.

The advantages of the present apparatus consist in the receiver-working even when the waves are very weak as the capacity of 7c is very small and consequently requires only an extremely small amount of static electricity to charge it and a tapper for do-- ing away with the connection produced by the waves is not necessary in the case of the arrangement shown in Fig. 2. Moreover the apparatus can be readily and quickly adjusted in correspondence with the strength of the waves employed. The apparatus may also be used with advantage in cable-telegraphy particularly in casesin which very long conductors are used and the signals or signs are indicated by means of alternating current or induced current.

The action of "the hereinbefore described apparatus depends entirely upon the elecwith one terminal of said receiving device, a conductor connecting that end of said coil at which said antenna enters into the same with the other terminal of said receiving device and a conductor connecting the other end of said coil to earth.

2. Receiving means for wireless telegraphy comprising in combination a coil, a receiving device, having parts of small capacity which are tobe charged by static electricity and discharged, terminals for said receiving device, an antenna passing through, said coil and connected with one terminal of said receiving device, a conductor connecting that end of said coil at which said antenna enters into the same with the other terminal of said receiving device, and a conductor connecting the other end of said coil to earth.

3. Receiving means for Wireless telegraphy comprising in combination a coil, a receiving device, terminals therefor, an antenna, a very thin wire wound in the form of a helix within said coil, connected with said antenna and with one terminal of said receiving device, a conductor connecting that end of said coil at which said antenna enters into the same with the other terminalof said receiving device and a conductor connecting the other end of saidcoil to earth.

4. Receiving means for wireless telegraphy comprising in combination a coil, a receiver having a local circuit, adjustable terminals therefor, means connected with one of said ter inals adapted to contact the other termin 1 under the action of electrical wavesand' to simultaneously closefs'aid local circuit and to return to its normal position under the action of gravity, an antenna passing through said coil connected with one of said terminals, a conductor connecting that end of said coil at which said antenna enters into the same with the other terminal of said re ceiver and a conductor connecting the other end of said coil to earth.

5. Receiving means for wireless telegraphy comprising in combination a coil, 'a recelver having a local circuit, adjustable terminals therefor, a lever connected with one of said terminals adapted to contact the other terminal under the action of electrical waves and to simultaneously close said local circuit.

coils at which said antenna enters into the same with the other terminal of said receiver, and a conductor connecting the other end of said coil to earth.

6. Receiving means. for wireless telegraphy comprising in combination a coil, a receiver, a fixed contact 2' therefor, a pillar g, a revoluble twoarmed lever 72. k mounted thereon and normally bearing against said fixed contact, a pivoted plate 0, two adjustable contacts 70 m thereon and adapted to be contacted by said lever, a local circuit connected with said pillar and'said fixed contact 41, a local circuit adapted for recording a paratus connected with said pillar and said adjustable contact m, an antenna passing 1 name to this specification, in the presence of through said coil connected with said contact two subscribing Witnesses.

HENRY HASPER.

is a conductor connectin that end of said coil at Which said anten ha enters into the GERHARD JAHR' 5 same With said pillar and a conductor coni WVitnesses:

nectlng the other end of said coil to earth. I J OHANNES HEIN,

In testimony whereof I have signed my 

